Oil burner control



NV- 24, 1942- A 'K G. E. sELDoN 2,303,235

OIL BURNER CONTROL Filed May 4, 19401 3 Sheets-.Sheet l .M m YI'GEQRGEESELDON ATTORNEY Nov/24, 1942.. G. E. SLDN 2,303,235

' A 'OIL BURNER CONTROL` l l Filed May 4, 1940' 's-sheeis-sneet 2 Fic.u.'

ATTORNEY Nav. 24, 1942. E.' SLDON 2,363,235 l Y 4QIL BURNER CONTROL YFiledMay 4, 1940 sheets-sheet 5 INVENTQ l GEOGE, E. SELDN `rather snuglytherein.

Patented Nov. 24, 1942 OFFICE on. BURNER CONTROL'A George E. Seldon,Brentwood, Mo., assigner to Carter Carburetor Corporation, a corporationof Delaware st. Louis, Mo...

- Application May 4,-11940, vsofriai No.sss,27c (01.13748) 13 Claims.v

This invention relates to liquid supply controls and consistsparticularly in acombination constant level and safety cut olfdeviceparticularly adapted 'for use 4with fuel supply systems` lfor oilburners. l

Constant level and safety cut oil devices for oil burners, asnow known,are provided with aA main constant level chamber controlled by a floatand valve and an auxiliary float chamber or' bucketv responsive tooverow from the main chamber to cut off the inlet as, for insta-nce,when the main inlet valve, valve seat, or actuating mech-v anism isfouled or does not operate properly for any reason. Usually theauxiliary float or bucket trips an over-center mechanism which thereuponpunches the main inlet valvev with aview to clearing'the valve seat andinsuring proper seating. In some cases, the overflow is ejected from theauxiliary chamber back into the main chamber by depressing the auxiliaryfloat which. fits Such devices as now in generaluse are' rathercomplicated, bulky, and expensive dueto the duplicate floats andchambers and the snap action trip mechanism and are not whollysatis-'factory since a single valve and seat are relied upon for cutting offthe fuel supply under normal operating, as well as, abnormal conditions.Furthermore, there -is no indication that the safety device has beentripped other than the maining figures, is housed within a generallyoval lcasing I6 having a curved partition 26 extendextinguishment of theflame in the burner.

In the present invention a unitary, compact mechanism is utilized forclosing the fuel feed passage when the .normal liquid level is attainedin the main constant level chamber and also in case of excessive levelAdue to fouling of the main inlet valve. The safety cut offmechanismoperates upon a separate valve and downwardly f level as thecontrol'device;

' 'gl 3 isa-vertical, longitudinalsection taken substantiallyfonline3--3 ofFig. A2.

VFigs and v5 aresubstantially vertical transverse sections takensubstantially on the correv spending section lines'ofvFlg. 2.

Fig. 6 is a detailedhorizontal sectional view showing a part of theoutlet valve controlmechanism. y y Figs. 7, 8, 9 and 10 are sectionalviews similar to Fig. 3,.Fig. 7 showing thechambersand pan substantiallyemptied, Fig.. 8 showing the pan manually lowered for. starting the flowthrough the device, Fig. 9 showing the safety valve closed due -tobuoyancy. of liquidroveriiowed from the pan into the auxiliary chamber,and Fig 10 showing the pan manually depressed to force the overflowfromthe auxiliary chamberthereinto.

Fig. 11 is a sectional view similar to Figs. v and 8, but showing amodification.y i j The type of fuel feed system V for which the presentinvention is particularly adapted,-is illustrated diagrammatically inFig. 1 and includes a\gravi ty tank I5, theA constant level and safety jdevice havinga casingl, a'furnace Il, a burner i I8, and suitableconnecting piping as at I9 and 20. Tank I5 is at a higher level than thecontrol device so that liquid will be fed by gravity thereto and toburner i8 which is at the same The control, as more clearly shown in thereing thereacross and dividing the same into a main chamber 2l and acircular auxiliary chamber 28 having an inwardly tapered lower portion.

Formed on the bottom' of the casing is a horifacing valve seat which isconstantly washed v by the fuel admitted to the main chamber so thatthis seat vwill be maintained free of sediment and foreign matter whichmay enter the valve chamber. In the safety cut off position, ay

part of the mechanism, normally located obscurely within the casing, isprojected into a clealy visible position outside the casing and thispart from the auxiliary chamber.

In the accompanying drawings which illustrate Fig. 2 is a viop view ofthe novel oontroi with the cover and other parts removed for clearerillustration.

The open end of tube 33 tits snugly within thread- I' ed aperture 30 sothat allfuel fed throughfthis is also utilized for forcing theoveri'lowed liquid zontal, tubular structure 29 threaded at oneend,

asiat 30, for attachment to the piping from the' supply tank and also'threaded at the other end asiat 3| for receiving the'threaded, closedend 32 of a perforated tube 33 having annular ribs or wings 34supporting a cylindrical screen 35.

aperture must enter the` interior of screen 35.

An inlet port lillk is located in the center of the oory o f mainchamber 21 and is surrounded Aby an upwardlyl projecting apertured Vbossstruc- Y ture 4| forming a valve chamber. At the sides of boss 4| areother apertured bosses 42` and 43 forming outlet 'portsr44 and 45A thebosses being -extended downwardly to form hollow ribs 46 and 4l ontubular structure 29. These ribs are threaded forI attachment to piping,as at 20 in Fig. 1, leading to the burner.. Where only one of inlet port40 and the lower edge of reduced portion 49 of guide sleeve or tube 48.The inlet valve is constantly urged upwardly by a coiled springll.

` Sleeve 48 is maintained in liquid tight seating` engagement with boss4| by means of clamping structure including a base portion 55 secured bybolts 58 (Figs. 2 and 5) to structure 4| 'adjacent the valve chambertherein. Base portion 55 .and guide sleeve 48 are provided withcomplementary shoulders as at 58 and, in the assembly, the undersurfaceof portion'55 is spaced above the 4up- 92 extending longitudinally 'ofthe casing near the upper portion thereof and over partition 28.This'arm is provided with a keyhole slot 93 for receiving the annularlygrooved'upper extremity of inlet valve stem 5|.' At the outer extremityof yarm 92, there is provided an aperture for slidably receiving a stem94 rigid with and projecting upwardly from the center of frusto conicalpan-like container 95 which closely corresponds,

in its outer dimensions and shape, to the dimensions and shape of thelower part of auxiliary chamber 28. A knob 98 is secured to the upper`extremitylof stem 94 and. a spring 91 is compressed between theundersurface of this knob per surface of boss 4| so that an-annularlyribbed shoulder 59 on the sleeve may be forced tightly against boss 4|by the bolts. A post 88 projects upwardly from base portion 55 and, atits upper extremity, has diverging arms 8| and 82'providecl withapertured bosses 88 and 84 for receiving the adjustable screws 85 and 86to be referred to hereafter, and apertured bosses 81 and 88 for slidablyreceiving outlet valve stems 89 -and 18'. Stems 89 and 18, in theirlower portions, are enlargedand hollowed to interiorlyreceive in closesliding engagement vertical tubes 1| and 12, re-

spectively, pressed into outlet bosses 42 and 48.

The stems are vented, as at 18.

Tubes 1| and 12 are provided with suitably shaped metering orifices asat 15 (Fig. 4) Knurled manual adjustment knobs 18 and 11 are secured tothe upper extremities of outlet valve stems 89 and 18 by means of capscrews 18. Valve stems 89 and 18 are constantly urged downwardly bymeans of coiled springs 19- and 88 compressed between the under surfacesof diverging arms 8| and 82 and the enlarged lower portions of the valvestems. Y

As shown most clearly in Figs. 4, 5 and 6, each manual control knob isprovided on its under surface with a pair of annular cam surfaces 82 and83 which cooperate, respectively with the projecting upper ends ofscrews 85 and 88 for controlling the adjustment of the outlet valves.Cam surface 82 slopes more gradually than surface 83 and these camsurfaces and screws 85 and 88 are arranged so that during the first partof the.

clockwise rotation of each knob from its fully closed position, as shownin Figs. 4, 5 and 6, inner' cam surface 82 rides upon the shorter screw85 so as to provide for gradual opening of port 15 and accurate controlof the slow fire or pilot feed. At a point during this rotation of theknob,

the longer screws 88 comes into contact with outer cam surface 83 on theknob and valve sternv 89 is thereafter raised at a more rapid rate. A

sharp .dip is provided at 84 at the end of the highest point in camsurface 88 so that after and the upper surface of arm 92 for yieldinglysupporting pan 95.

As best shown in Figs. 2 and 4, a low wall 88 extends across'one cornerof main constant level chamber 21 and forms a well 99 therein. siphontube |8| extends upwardly from within well'99 through'a recess |88 inpartition 28 and downwardly into pan 95 and forms a hydraulic connectionbetween the pan and main chamber. The side walls of recess |88 aregrooved as at |82 for tightly receiving a thin collar |83 formed on thesiphon tube so as to provide a substantially liquid tight fit therewith.This'arrangement provides for easy assembly of the siphon tube in itsproper position.v The upper edge of low wall 98 is located slightlyabove the level of outlet port 15 so that the well cannot be drainedthrough the port and the corresponding end of the Siphon tube will beconstantly submerged in liquid after the control has been placed inoperation.

A cover |85 is provided with suitable openings |88, |81 and |88 foraccommodating knobs 18,

. 11 and 96, respectively, and is secured to the cas- Aing byl means ofscrews |89.

The control operates as follows: When the casing is empty, as when firstinstalled in an oil burner system, or when the liquid level in pan 95 isat or below the level V (Fig. '1) andchamber 28 is empty, springs 91 andH8 support arm 92 and the pan in their uppermost positions, as shown inFig. 7, with valve 53 closed and knob 98 projecting substantially abovecasing cover |85 so as to be clearly visible. Preferably this knob willbe painted bright red so as to con-- trastwith the usual dark coloringof the casing and'cover. If the control is then connected to pipingleading fromthe oil tank and to the burner, as in Fig. 1, and knob 98 ismanually depressed with its upper surface at the level of this pointpasses screw 86 the knob again drops onto the shorter screw 85 to closethe valve. This prevents lifting of valve stem 68 beyond the full openposition with relation to port 15. When the knob is fully rotatedanti-clockwise so as to bring shorter screws 85 into engagement with thelowest point on cam surface 82, the lowered, tapered extremity of thevalve stem will be firmly seated against the upper edge of boss 42 or43.

the casing cover, as shown in Fig. 8, double valve 52, 53 will be movedto an intermediate, open position between the valvel seats formed on theupper edge of port 48 and the lower edge of sleeve 48 so that oil may owinwardly through tube 33 thence upwardly through screen 35, port 48,boss 4I, sleeve 48, and openings 48a into main constant level chamber21. y

When the oil in chamber 21 reaches approximately the level Z (Fig. 8),it'will flow through siphon tube |8| into pan 95. Spring |I8 iscalibrated to yield when oil in pan reaches the level T to permitlowering of the pan, arm 92 and valve stem 5| and closing of valve 52against port 48. After the outlet valve is opened, oil in the mainconstant level chamber and pan will become equalized approximately tothe level T-T (Fig. 3). Under normal operating conditions, springA 91Yon the pan stem 94 is strong enough to support the weight of the pan andcontents of the pan and arm 92 will rise and fall underYV the inuence ofthe weight of liquid therein and spring I I0, opening and closing valve52 to main-V tain the level T-T in chamber 21.

During normal operation, the level T in the pan remains sensitivelyconstant with vrespect to the floor of the casing, due to balancing of,theA

pan by spring l I0, which spring is accurately calibrated for thispurpose. In fact, the absolute level of liquid in the pan will -varysubstantially less than does the level in the usualfioat controlledconstant level chamber in whichanincreased demand or decreased supplyhead necessarily results in lowering of the supply level in the oatchamber to permitfurther opening ofthe inlet valve. the constant levelchamber is on the order of 1/2", as is the usual case with this type ofdevice, a

variation in level of even 11s" results in a material change in the rateof fuel supplied to the` burner. I have found that fuel controldevicesof theA present type having a level controllingV float, as now `ingeneral use, produce Va 'variation as high as 20%, for a given settingof the outlet-valve, as the main fuel'tank is drained.' Pan 95, beingfrusto-conical, `has straight sides, and these slope sharply or, inother words,

' approach vertical' so that changes in volume of.

liquid in the pan are nearly directly proportional to correspondingchanges in depth of the contained liquid. Since the distortion of aspring is, according to Hookes Law, directly proportional to the stress,such shaping of the pan facilitates designing of spring H0 so that theabsolute level of liquid in the pan remains very nearly constant.

This is aided,further, by the small movement of valve member 52,53 andthe consequent small,

though magnified, movement of the pan'duringY normal operation. In theillustrated embodi- Where the normal head available in level T `(Fig.3). Whenrinstrument VI l2 is then" removed, springs 91 and H0 willexpand so as toV return valves 52, 53 to an` intermediate positionvbetweenport' 40 andthe lower edge ofV sleeve (I8 and raise the pan. Oilwill again flow through port 40 to the levels T in both the main chamberand pan, as in Fig. 3. However, if valve 53 should seat when tool I l2is removed after Vreturn of the overowed oil to the'fpan, knobs 96willbe visible,

as 'in Figs. 7 and 9, and the control may be re-v started, asin Fig. 8.If the capacities of the pan and auxiliary chamber'and the weight ofpan95,

,. arm 92,', and stem 5| are accurately adjusted relative tothe strengthof spring Il, this will not be necessary. The overflow level U (Fig, 9)is close'tothe edge of the pan and the clearance be- Vtween thepan andwall of chamber 28 is small sofas to insure rapid spilling of the overowoil into Ythe pan when knob 96 is depressed and thus 'prevent the entryof air into the Siphon tube.

Incase of puncturing of the pan,eupper valve 53, Vof course, will belrmlyforced against its seat by spring lll). This spring 4is preferablymade of such rugged proportions as to practically eliminate thepossibility of failure thereof. Also,

Ywhen lthe device is empty before being setinto operation', or becauseof a leak in the-system,

'- spring H0 will hold valveV 53 in its safety, closed ment, v alve 52,53 moves 'about 11g ofan inch,

and the corresponding movement of the pan dur` ing normal'operation isabout 1/2 of an inch or less than 1/2 the total depth of the pan.

If, for'any reason, oil should continue to flow into the casing when pan95 and valve 52 are lowered as in Fig. 3, the oil in the main constantvlevel chamber and in pan 95 would then rise further so as to overow thepan. vWhen the overflow in chamber 28 reaches approximately the level U(Fig. 9) the weight ofv pan 95and contents will be relieved due to thebuoyancy of the Y overflow oil, permitting spring H0 to lift the pan andvalve stem 5 I so as to cause upper valve surface 53 to seat against thelower extremity of sleeve 48, closing the inlet passage. Thereafter,

oil in the constant level chamber 'will drain through the outlet valveinto the burner pan until the level Y (Fig. '1) is reached in the mainchamber which corresponds approximatelywith the lower edge of meteringport 15. At the same A time oil will be drained from pan 95 throughsiphon tube llll until the level in the mainportion of chamber 21 isbelow the upperedge of well 9,9. In the fully drained position, as shownposition. This is especially important since it preventsl the supplyingof fuel to the burner, for instance during lling of the main tank,'untilthe level controlY is manually set, as in Fig.V 8. The form in Fig. 11functions similarly to the vfirst form, but differs structurally inthat' liquid entering port 40-passes upwardly through valve guide sleeve48h and thence through tube I l5 into pan 95.l In order tov prime orstart the control, liquid Yisjpoured into main chamber 31 to the level Zso as to fill Siphon tube |01, but thereafter the lvalves K are actuatedautomatically, both under normal and abnormal conditions-and, after thesafety cut off the mechanism may be reset by fullydepressing button 96,as previously described.

The control is substantially more simple and compact than 'similardevices now known and provides for effective control of the normal fuellevel in the constant level chamber as well as a sure safety cut orf.The downwardly facing valve seat on sleeve 48 being constantly washed bythe oil will remain free of impurities and sediment which may enter thevalve chamber. The exclusive use of all modifications as come within thescope of the appended claims is contemplated.

I claim:` Y

1. In a liquid supply control, a main chamber 1 member, an auxiliarychamber, a pan member in Fig. '1, oil will remain in the pan 95 at thelevel V so as to submerge the .corresponding end of the siphon tube.- Asthe opposite end of the tube will remain submerged in oil in well 99,the siphon tube will remain full of oil ready for 'resetting of themechanismA without first driving air therefrom.

in said auxiliary chamber, an hydraulic connection between said members,means for feeding liquid to one of s'admembers comprising an inletpassage and valve means therefor, and valve actuating mechanismvincluding an` operative In order to re-set the control after the safetyconnection between said valve 'means and said pan member, said mechanismfunctioning to close said inlet passage responsive to the weight ofliquid in said pan member and also responsive to the buoyancy of theliquid overflowed into said auxiliary chamber, upon said pan member.

2. 1n a liquid supply control, a main chamber and an auxiliary chamber,an outlet port in said main chamber, a pan in said auxiliary chamber, aduct connecting said main chamberv and said pan, means for supplyingliquid to said main chamber and said pan including a passage, valvemeans'in said passage, means normally urging said valve means to closesaid passage, and an operative connection between said pan and saidvalve, means, said valve closing means and said connection beingresponsive to the weight of a predetermined quantity of liquid in saidpan to urge said valve means closed and to thexweight of a lesserquantity of liquid in said pan to open said valve means, said valve'closing means and said connection also. functioning to close said valvemeans when theweight of said pan and the said pan in liquid therein isrelieved due to buoyancy of liquid overowed from said pan into saidauxiliary chamber. e

3. In a liquid supply control, a main constant level chamber ymemberhaving an outlet port,'an auxiliary chamber, a pan member in saidauxiliary chamber adapted to overflow 'thereintq a duct disposed totransmit liquid between said main chamber member and said pan memberunder operating conditions, a passage for supplying liquid to one ofsaid members, valve means in said passage, a spring normally urging saidvalve means toward a rst position to close said passage, and aconnection between said valve means and said pan member for opening saidvalve means when the Weight of said pan member and liquid contentssubstantially balances said spring, said connection` being responsive tof a greater weight of liquid in said pan member to distort saidspringand urge said valve means to a second position to close saidpassage.

4. Ina liquid supply control, a main constant level chamber having inletand outlet passages, a valve device in said inlet passage, an auxiliarychamber, a duct hydraulically connecting said pan and said chamber, apan in said'auxiliaryy chamber, mechanism responsive `to the weight of apredetermined quantity of liquid in said pan -to move said valve deviceto a closed'position and to a lesser weight of liquid in said pan toopen said valve, and a spring normally urging `said valve device awayfrom said position and functioning to move said e device to 1a secondclosed position when said weight is relieved by .o

the buoyancy of said pan in liquid overflowed into said auxiliarychamber upon said pan.

5. In a liquid supply control, a main constant level chamber, anauxiliary chamber, a pan closely tting but vertically movable in said 60liquid from said pan when said valve means is closed, said pan and saidoperative connection being responsive to the Weight of a predeterminedquantity of liquid in said pan toactuate said valve device and maintaina constant level in said main chamber and to close said valve devicewhen liquid in said pan overflows into said auxiliary chamber, and saidpan being manually depressible to expel liquid from said auxiliarychamber back into said pan after said pan has been drained.Y Y v 6. In aliquid supply control. a casinghaving a partition forming main andauxiliary chambers,

5 an inlet vand an outlet in said main chamber, a

valve device in said inlet, a pan movably carried in said auxiliarychamber, a Siphon tube mounted independently of said pan and extendingfrom a point inside said pan, and substantially below the top thereof,over the edge of said pan and liquid is collected in said pan tomaintain a constant'level in said main chamber above the level of theextremities of said tube.-

7. In a liquid supply control, a main chamber member having an outlet, avertically movable pan member, means for supplying liquid to both ofsaid members including a passage opening into one of said members and aSiphon tube supported independently of said pan member and extendinglfrom* the interior of said last-mentioned member through the wallthereof above the liquid level therein and thence into the other member,and mechanism for controlling said valve device responsive to the Weightof liquid in said pan to maintain a constant level of liquid in saidmain chamber member.

immersed in liquid in said well whereby air is r o operative connectlonbetween said pan and said valve device to operate the latter responsiveto the Weight of liquid in said pan and maintain liquid in said mainchamber ata constant level above the opening of said tube thereinto,said tube being wholly below. the upper edge of said partition wherebyliquid may flow through lsaid tube in starting the control withoutoverflowing from said main chamber into said auxiliary r chamber.

10. Inl a liquid supply control, a casing having an outlet port, aiioatable container in said casing,v means yieldingly supporting saidcontainer, means to concurrently supply liquid to both said casing andsaid container including an inlet passage,l valve means in said passage,and mechanism operatively connected to said valve means and arranged tooperate said valve' means responsive to the weight of said container and5 liquidv contents to maintain a substantially constant level in saidcasing and responsive to the buoyancy of a predetermined excess ofliquid in said casingto provide for emergency closing of said valvemeans.

11. In a liquid supply control, a casing including a main constant levelchamber and an auxil- Aiary chamber, a pan closely fitting and movablein said auxiliary chamber, means to supply liquid to said main chamberincluding a passage having a valve therein, means to control said valveduring normal operation to maintain liquid in said main chamber at asubstantially constant level, means to conduct liquid into saidauxiliary chamber when the liquid in said main chamber reaches anabnormal level, said pan having an operative connection with said valveand being responsive' to the presence of a predetermined quantity ofliquid in said auxiliary chamber to close said valve, and an elementprojecting from said pan and substantially concealed by the casing wallwhen the control is functioning normally, said element being movable toan abnormal, clearly visible position beyond said wall when said valveis abnormally closed, as described, said element being manually movablefrom said protruded position to depress said pan and to transfer liquidfrom said auxiliary chamber thereto, and means to drain said pan.

12. In ailiquid control, a casing having a partition forming main andauxiliary chambers, said main chamber having an outlet, a movable pan insaid auxiliary chamber, a passage for supplying liquid to said mainchamber and said pan, an hydraulic connection between said main chamberand said pan for maintaining'liquid at related levels therein, valvemeans in said passage,v and an operative connection between said pan andsaid valve means for maintaining a constant level of liquid in said mainchamber according to the weight or liquid in said pan, said hydraulicconnection being supported solely by said casing and independently ofsaid pan whereby said pan' may operate without mechanical restraint dueto said connection.

13. In a liquid supply control, a casing having main and auxiliarychambers, a pan in said aux.- iliary chamber, a passage to supply liquidto said main chamber and said pan, a valve in said passage, and'operative mechanism between said pan land said valve functioning toactuate said valve normally responsive to the weight of liquid in saidpan to maintain a constant level of liquid in said main chamber, saidmechanism functioning abnormally in accordance with the buoyancy ofliquid in said auxiliary chamber to close said valve when said panoverflows.

GEORGE E. SELDON,

